• 1 L water (may be less for denser concentrate - used this much for simpler measuring)
• 10 Lipton Green Tea bags - cut the strings, boil in that water for 5 minutes
• 7 ml citric acid crystals (? g)
• 8 ml potassium citrate crystals (Ostrovit, 4.8 g)
• 2 ml vitamin C powder (Adox group, 1.2 g)
• 4 ml caffeine powder (Adox group, 1.2 g)
• 40 mg potassium sorbate (Browin, not strictly necessary if consumed early)
• 250g erythritol
• 75g xylitol

Makes 4 L of resulting drink, mix 1:3. Saturate with ~4 bar of CO2 after the mix has been cooled down to 4 C. Does not foam, concentrate should keep rather well due to antibacterial and antifungal contents. High caffeine content warning.

Yes, this is not mate, but it's chaicola modeled on Club-Mate Ice-T. Will be further improved and contain actual yerba mate once I get it.